ـی is the form that follows words ending in consonants. Adjectives ending in the short vowel ـه ‎(-e) will use the form ـگی ‎(-egi) for their derived nouns, while nouns ending in ـه ‎(-e) will usually add the non-joining ای ‎(-i) to form their derived adjectives. Both nouns and adjectives ending in the long vowels ـا ‎(-â) and ـو ‎(-u) will use the form یی ‎(-yi)

As a derivational suffix, ـی and the above-mentioned alternative forms take the stress in a word, as in خورشیدی ‎(xoršidí, “solar”). As the marked indefinite or relative definite suffix, the stress remains on the root of the word, as in خورشیدی ‎(xoršídi, “a sun / the sun which”)